The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Previously, polyurethanes based on two or more macrodiols which are chemically different have been reported. This has been achieved by using a mixture or a blend of the macrodiols for making the polyurethane, and employing either a one-step or a two-step polymerisation procedure. This approach has a number of disadvantages including: in most cases, if the macrodiols are not miscible, the resulting polyurethane is compositionally heterogeneous; only a limited number of macrodiol combinations can be used to make polyurethanes with good mechanical properties, and the segments from each of the macrodiols are randomly distributed within the polyurethane chain (often resulting in polyurethanes with poor mechanical properties); and the incorporation of higher molecular weight macrodiols or macrodiamines are limited to polyols such as polyether, polyester or polycarbonates.
There is a need for identifying alternative block copolymers for use in polyurethane or polyurethaneurea elastomer compositions for preparing various polymer products with a broad range of mechanical properties. The alternative block copolymers may address one or more disadvantages of previous approaches.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.